Demand control ventilation is recognised as being a method of ensuring a building is ventilated cost effectively while maximising indoor air quality. Sensors are used to continuously measure and monitor ambient conditions in the conditioned space and provide real time feed back to the zone controller which adjusts the fan speed modulating the ventilation rate to match the specific use and occupancy of the building.
Building ventilation systems often operate at constant or pre-determined ventilation rates regardless of the occupancy level of the building. Ventilation rates are normally based on maximum occupancy levels resulting in consequent energy wastage. The energy wastage is not only due to the fan operation, but also includes the energy used to condition the air, whether in heating or cooling mode. Significant energy savings are made by effective DCV which ensures that the ventilation rate continuously matches the current occupancy rate and varying ambient conditions.